1. Field of the Invention
The present invention relates to an electronic camera, more particularly a camera in which rewinding of a film is electrically carried out and an aperture is operated independent of a shutter.
2. Description of the Prior Art
When rewinding of a film is stopped with an leader end of the film remained a little outside a film cartridge for a specified time in rewinding of the film and a camera back is opened during this specified time, the film cartridge with the leader end of the film remained a little outside the film cartridge can be taken out from the camera body and, when the specified time has passed without opening the camera back during counting this specified time, rewinding of the film is carried out, rewinding of the film is stopped after the leader end of the film is completely retracted into the film cartridge and the film cartridge into which the leader end of the film has been completely retracted can be taken out from the camera.
Conventionally, this type of film rewinding apparatus which has been proposed is disclosed in the Examined Patent Publication No.60890-1988 (hereafter referred to as "Publication A" and the Unexamined Patent Publication No.232433 (hereafter referred to as "Publication B.).
In case of film rewinding operation by the system disclosed in Publication A, if the film is completely used (the film is taken up to the final frame), the film is rewound until the film is completely rewound into the cartridge and, if halfway rewinding operation is carried out when the film is not yet completely used (the film is not taken up to the final frame) so that the film which has been used with a certain length of the remaining part is temporarily replaced with another film and subsequently the film can be easily drawn out when using it later, rewinding is stopped with the leader end of the film kept drawn out of the cartridge.
In case of the system disclosed in Publication B, an operating member is provided outside the camera body which allows to select a mode in which rewinding is stopped after the film is rewound until the film is completely rewound into the cartridge or a mode in which rewinding is stopped with the leader end of the film kept drawn out of the cartridge by changing over this operating member.
Accordingly, in case of the system disclosed in Publication A, the film is completely rewound into the cartridge after the film is completely used. For example, in the developing process of the film by the photographer himself, it is troublesome to draw out the leader end of the film from the cartridge chamber and it will be necessary to draw out the leader end of the film even when the film has been completely used (up to the final frame of the film has been exposed).
In case of the system disclosed in Publication B, it is necessary to provide an operating member and switches for selecting whether or not the leader end of the film should be kept drawn out of the cartridge when rewinding the film and it is difficult for a beginner of photography to determine the above selection. In addition, this system is disadvantageous in that the operation is troublesome and the construction of the camera is complicated.
Moreover, in case of a camera provided with a lens shutter and an aperture which operates independent of the lens shutter, the opening and closing time of the shutter need be changed in accordance with the diameter of the aperture when executing the photography at the specified shutter speed.
Conventionally, in case of a camera provided with the lens shutter and the aperture independent of the shutter, the exposure control has been carried out at a single opening and closing time regardless of the diameter of the aperture when executing photography at a certain shutter speed.
In this case, if the shutter speed is higher to some extent, the shutter speed becomes slower along with stopping down of the aperture even though the shutter opening and closing time is the same for each exposure and therefore there has been proposed a camera which compensates the exposure by stopping down the aperture to be smaller as much as slowing down of the shutter speed than the specified diameter.
Accordingly, in case of a camera which control the exposure with an aperture having an accurate diameter and a single shutter opening and closing time, the shutter speed is gradually slowed down along with stopping down of the aperture as the shutter speed is higher though a substantially accurate shutter speed is obtained as far as the shutter speed is within a range of low speed.
As shown in, for example, FIGS. 73 and 74, the shutter speed with the minimum aperture of F22 as shown in FIG. 74 is slower than he shutter speed with the open aperture of F2.0 as shown in FIG. 73 even at the same shutter opening and closing time. Therefore, it has been unable to obtain an appropriate exposure in high speed shutter operation.
On the other hand, in case of a camera which compensates the exposure by stopping down the aperture to be smaller as much as slowing down of the shutter speed than the specified diameter, a disadvantage that the shutter speed is slow even though an appropriate exposure is obtained for a combination of the specified aperture and shutter speed in the range of high shutter speed has not been eliminated and therefore there has been a problem that a blur of a subject would be caused and an error of compensation would appear in the range of low shutter speed.